Tech Tip: Selecting the perfect lens is as easy as… 1, 2, 3


Tips from our experts


Selecting the perfect lens is as easy as... 1, 2, 3
As today’s projection technology continues to advance, updates, enhancements, and modifications have all added to the many options available to the user.  Through precision and craftsmanship, a diversity of lenses allows projectors to serve as flexible solutions for a wide variety of applications.  So exactly how do you choose the perfect lens for every application?


When specifying a lens for a project you will need at least two of the following values: Screen Width, Throw Distance, or Throw Ratio


With any two of these values, the third can be calculated.  By taking a few minutes to gather this information, you can assure your first installation is a correct installation.


Screen Width: The dimension used in throw ratio calculations is always the width of screen (never the screen diagonal).
Throw Distance / Lens Throw Ratio = Screen Width
Example: (410” / 2.5 = 164”)
Throw Distance: Always measured from the front center of the lens to the first perpendicular point of contact on the screen.
Screen Width X Lens Throw Ratio = Throw Distance
Example: (192” x 2.4 = 460.8”)
Throw Ratio: Throw Distance / Screen Width = Lens Throw Ratio
Example: (240” / 100” = 2.4)
Although these calculations are simple and straightforward, it is easy to make a measurement or calculation mistake that could lead to the incorrect lens being selected.  The most common mistake is when the lens ratio is rounded up or down.  The rule of not rounding values applies to all calculations; weather your calculating screen sizes, throw distances, or throw ratios; it is always best to take accurate measurements.  To add an extra measure of installation security, we recommend projectors not be located such that the lens is at either extreme of its throw ratios.


Keeping it simple:
  1. Accurately measure 2 out of 3 - Screen Width, Throw Distance or Throw Ratio
  2. Using the formulas provided above, do the math accurately with no rounding 
  3. Choose the lens that has the most flexibility on both sides of the required Throw Ratio.  If the required throw ratio is at the extreme range of the lens, then adjust throw distance or screen size accordingly. 
Have a question or just want to be sure you have chosen the perfect lens fit?  Call on Digital Projection's Application Support team; that's what we are here for!

Need Application Support?

Specializing in pre-and post-sales and installation questions and support on items such as product selection, lens options, projector setup/operation, and more.

8:30 AM - 5:30 PM EST, Monday-Friday

Phone: 770.420.1350